In many medical procedures, an individual is connected to an infusion set for administration of medicaments and liquids. However, periodically it is required to obtain a blood sample from the individual for carrying out laboratory tests.
It is thus required that such blood samples contain only so-called fresh blood drawn from the patient, i.e. Without residual medicaments or liquids from the infusion set on the one hand and, on the other hand, be freshly drawn from the individual.
For this purpose, there are a variety of blood sampling devices which are typically used with a suitable blood drawing port or valve as known per se.
A blood sampling device must be capable of first obstructing flow through the infusion set and then drawing a sufficient amount of liquid residual in a portion of the tubing of the infusion set extending between the sampling device and the individual, where the sufficient amount is defined as being at least slightly more than the volume confined within said tubing portion.
Various blood sampling devices are disclosed, for example, in U.S. Pat. Nos. 4,673,386, 5,324,266, 4,105,500, 4,703,763, 4,838,855 and 5,002,066.
It is an object of the present invention to provide a novel and improved sampling device suitable for use in particular in conjunction with an infusion set.